General Units with UART Port Availability

UART communication port availability, common applications and identification guidance

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Overview

This article provides information about which General air conditioning units include a UART (Universal Asynchronous Receiver/Transmitter) communication port, what the port is used for, and how availability varies across models and production years.

1. What Is a UART Port?

The UART port is a communication interface located on the indoor unit control board. It may allow connection of compatible accessories and communication devices.

  • Optional Wi-Fi modules or zone-control interfaces
  • Compatible third-party control or communication interfaces
  • Diagnostic or service equipment on supported models

Accessories that may use a compatible UART connection include:

  • anywAiR® Wi-Fi adaptors
  • UTY-TFSX or UTY-TFNXZ2 interface modules
  • Intesis and approved third-party communication gateways

2. Units Equipped with UART Ports

Production YearSeries / ModelsUART Port AvailabilityNotes
2022 to currentWall-mounted split systems, including selected ASTG, ASTH and ABTG seriesTypically one UART portConfirm compatibility using the model-specific wiring diagram or accessory documentation.
2022 to currentCassette and ducted systems, including selected ARTC, ARXC, AUTG and ARY seriesOne or two ports on selected modelsSome models provide additional connectivity for compatible accessories.
2022 to currentSelected VRF indoor unitsModel dependentUART availability and intended use must be confirmed against the applicable technical documentation.
Before 2022Selected models onlyNot standard across all modelsCheck the indoor unit wiring diagram, service manual and accessory compatibility list.
Important: UART availability should not be confirmed solely from the unit's production year. Always check the exact indoor model number, wiring diagram and compatible accessory documentation before installation.

3. Dual UART Ports

Certain commercial indoor units and ducted models may include two compatible communication connectors. Depending on the model, this may allow more than one approved accessory to be connected.

Possible applications may include:

  • A compatible Wi-Fi adaptor
  • An approved wired control interface
  • A compatible third-party gateway

The presence of two connectors does not automatically mean that any two devices can be connected simultaneously. Confirm the permitted combination, connector assignment and accessory limitations in the applicable installation documentation.

4. Identifying the UART Port

The connection is generally located on the indoor unit control PCB. Connector labels vary by model and may include:

CN105 CN106 CN107 CN152

The connector may be a three-pin or four-pin socket. Depending on the model and accessory, the connection may provide power, ground and communication conductors.

Do not rely on connector labels or pin count alone.
Refer to the indoor unit wiring diagram and accessory installation instructions for the exact connector location, voltage, pin assignment and communication function.

5. Common Uses

Accessory / FunctionMay Use UARTDescription
anywAiR® Wi-Fi adaptorYesProvides compatible app-based control where supported by the indoor unit.
Wired control interfaceModel dependentSome interfaces use a dedicated communication connector rather than a UART accessory port.
Third-party interfaceYes, where approvedEnables compatible BMS, Modbus or home-automation integration.
Service or diagnostic equipmentModel dependentUsed for supported configuration, monitoring or diagnostic functions.

6. Service and Installation Notes

Confirm the exact model.
Port availability, connector labels and accessory compatibility vary between indoor units.
Isolate power before installation.
Ensure the indoor unit power supply is safely isolated before accessing the PCB or connecting an accessory.
Use approved accessory combinations.
Do not connect multiple devices to one connector or use a splitter unless the arrangement is specifically approved.
Check connector voltage and pinout.
Connecting an accessory to the wrong PCB socket may damage the indoor PCB, accessory or communication circuit.

7. Summary

Unit TypeTypical AvailabilityRemarks
Residential wall-mounted splitCommon on newer modelsConfirm the indoor model and accessory compatibility.
Ducted or cassetteOne or more connectors on selected modelsAdditional connectors do not guarantee simultaneous accessory support.
VRF indoor unitVaries by model and seriesRefer to the applicable technical and accessory documentation.
Older indoor modelsVariableA UART-compatible connector may not be fitted.
Final Check
Before ordering or installing any Wi-Fi adaptor, interface or third-party gateway, confirm the complete indoor unit model number and consult the applicable wiring diagram and accessory compatibility information.
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